Question

I have tried invoking Ant programmatically, but I am encountering this error

Exception in thread “main” java.lang.NoClassDefFoundError: org/apache/tools/ant/launch/AntMain

I tried to run build.xml separately using the console and via right-clicking it in eclipse running as ant build. It runs with no problems.

My sample ant testing class

public class AntTest {
    public static void main(String[] args) {
        File buildFile = new File("build.xml");
        Project p = new Project();
        p.setUserProperty("ant.file", buildFile.getAbsolutePath());
        p.init();
        ProjectHelper helper = ProjectHelper.getProjectHelper();
        p.addReference("ant.projectHelper", helper);
        helper.parse(p, buildFile);
        p.executeTarget(p.getDefaultTarget());
    }
}

My sample build.xml

<?xml version="1.0" encoding="UTF-8"?>
<project name="testproject" default="test" basedir=".">
    <target name="test">
        <echo message="Hello World" />
    </target>
</project>

What am I missing?

Answer 1

Make sure that the ant libraries are in your classpath.
It seems, that ant-launcher-VERSION.jar (where Version is the ant version you are using) is missing in your classpath.